BY THE REV. W. B. CLARKE, M.A., F.G.S., &c. 281 



matter there can be no doubt. And some geologists have 

 ventured on the haphazard conclusion, that it will be found under 

 almost all large areas of bog or turf. We already know, that the 

 bogs of Ireland have supplied materials for candles, and there are 

 minerals also in New South Wales, such as Bog-butter, which 

 have resulted from decomposition of vegetable matter in peat. 



A mineral of this kind, belonging to the waxy and resinous 

 species, I showed some time ago to Professor Smith. It came 

 from the neighbourhood of Twofold Bay. A mineral of a like 

 character has more recently been discovered at Wettin, in 

 Germany, in the Royal Coal Mine, in association with much rock 

 oil. 



In the volume for 1863 of "Good Words," a very useful 

 periodical edited by Dr. Macleod, there is an excellent paper by 

 Professor G. Rogers, of Glasgow, on Coal and Petroleum ; in it 

 he supposes the rock oil to be produced by coal seams affected by 

 pressure and internal heat, the lowest coals nearest the igneous 

 source being converted into anthracite. He thinks the distillation 

 has caused the oil to accumulate in deep fissures and subterranean 

 reservoirs below the coal formation, and even as low as the 

 Silurian rocks, and that it is poured out from those reservoirs 

 by the same mode of action as produces Artesian springs. 



Another author has supposed it to be an exudation from coral 

 reefs, a proposition which originated in a mistake and which 

 requires little refutation. A French geologist of eminence to 

 whom I have already alluded M. Virlet d'Aoust arguing 

 against another opinion (that, because some of the oils have a 

 peculiar character they are allied to animal matter, which appears 

 to be the case with oil distilled from the Cannel coal under 

 Mount York, in New South Wales), has put before us some facts 

 which cannot be set aside by mere conjecture.* He even contro- 

 verts the idea of an origin in coal, which two distinguished 

 chemists of Germany, Messrs. Turner and Reichenbach, have held 



* Nevertheless, we must not overlook what Sir R. I. Murchison says in 

 his " Siluria " (3rd ed. pp. 282-3 and 560-1) of fossil-fish-bearing beds pro- 

 ducing bitumen at Caithness, and of the fish-bearing beds of the High Alps 

 from which oil has been distilled. See, also, his paper in Proc. Geol. Soc. I. 

 139. [3rd April, 1829.] 



